In recent weeks, tensions have soared as Russia massed more than 100,000 soldiers and heavy weapons at its border with Ukraine, raising fears of an invasion. After building up its troops, Russia called on NATO to pull back its forces and weapons from Eastern Europe and permanently block Ukraine, a former Soviet state, from becoming a member. The US and NATO, however, rejected Russia's demand for a veto on Ukraine's potential membership, and instead accelerated its arms supplies to Ukraine. On Wednesday, the United States said it is going to deploy more troops in Eastern Europe.